Lab News & Scientific Highlights

Imaging strain in crystalline materials with high resolution can be a challenging task. Researchers demonstrate an original use of X-ray ptychography for this purpose: ptychographic topography.

In a study published in Nature Communications, researchers at the NHC Key Laboratory of Systems Biology of Pathogens in Beijing, China, in collaboration with the Paul Scherrer Institut characterize the interactions of SARS-CoV-2 orf9b and human TOM70 biochemically, and they determine the 2.2 Å crystal structure of the TOM70 cytosolic domain with a bound SARS-CoV-2 orf9b peptide.

Myelin 'insulates' our neurons enabling fast signal transduction in our brain. Myelin levels, integrity, and neuron orientations are important determinants of brain development and disease. Small-angle X-ray scattering tensor tomography (SAXS-TT) is a promising technique for non-destructive, stain-free imaging of brain samples, enabling quantitative studies of myelination and neuron orientations, i.e. of nano-scale properties imaged over centimeter-sized samples.

In a study addressing the global health threat of drug resistance, researchers at the Biozentrum, University of Basel, have revealed how a new antibiotic, Darobactin, binds to the external membrane of gram-negative bacteria.

During the week of March 15 – 19, we had the pleasure to welcome 20 international PhD students, PostDocs and assistant professors at PSI, taking part in the first virtual HERCULES SCHOOL on Neutrons & Synchrotron Radiation.

The first experimental observation of three-dimensional magnetic ‘vortex rings’ provides fundamental insight into intricate nanoscale structures inside bulk magnets, and offers fresh perspectives for magnetic devices.

Dr. Manuel Guizar-Sicairos, beamline scientist at the cSAXS beamline, was elected as a Fellow Member of The Optical Society (OSA) for seminal contributions to methods and applications of coherent lensless imaging, ptychography, x-ray nanotomography, and new modalities of x-ray microscopy.

A group of EMPA and ETH Zürich researchers have developed a new method to directly write ink made of silica aerogels in 3D. Thanks to X-ray phase contrast tomography at the TOMCAT beamline they characterized the resulting printed material with different compositions. Their results were published in Nature on August 18, 2020.

Metal-based nanoparticles are a promising tool in medicine – as a contrast agent, transporter of active substances, or to thermally kill tumor cells. Up to now, it has been hardly possible to study their distribution inside an organism. Researchers at the University of Basel in collaboration with the TOMCAT team have used phase contrast X-ray tomographic microscopy to take high-resolution captures of the nanoparticle aggregation inside zebrafish embryos.

The study was published in the journal Small and featured on the cover of its current issue.

The Dikic group at the Goethe University in Frankfurt am Main, Germany has published the first results following the opening of the "PRIORITY COVID-19 Call” at SLS. 

The team of Prof. Thomas Hermans at the University of Strasbourg in France managed to create wall-less aqueous liquid channels called anti-tubes. Thanks to X-ray phase contrast tomography at the TOMCAT beamline those anti-tubes could be observed in 3D. The exciting results were published in Nature on May 6, 2020.

Microcalcifications are a common sign in mammography. For example, in 90% of ductal carcinoma in situ microcalcifications are the first and unique sign indicating the presence of the lesion. Nevertheless, up to around 50% of the resulting biopsies reveal a benign lesion, a 'false positive'. Researchers were able to show now that breast microcalcifications detected in tumors have specific chemical and crystalline features different from those observed in benign samples. Moreover, microcalcifications detected in tumors but located outside the lesion show malignant features too. This indicates that cancer influences the surrounding tissue even if it exhibits apparently healthy morphological features. These results indicate that the biochemical differences between benign and malignant microcalcifications can be potentially identified by light-based tools, able to investigate microcalcifications inside the breast without performing biopsies.

Update of the SLS MX beamline operation during the COVID-19 period

The TOMCAT beamline at the Swiss Light Source specializes in rapid high-resolution 3-dimensional tomographic microscopy measurements with a strong focus on biomedical imaging. The team has recently developed a technique to acquire micrometer-scale resolution datasets on the entire lung structure of a juvenile rat in its fresh natural state within the animal’s body and without the need for any fixation, staining or other alteration that would affect the observed structure (E. Borisova et al., 2020, Histochem Cell Biol).